詳細

中井　英隆 （ナカイ　ヒデタカ）

  • 理工学部 エネルギー物質学科　教授
Last Updated :2024/04/25

コミュニケーション情報 byコメンテータガイド

  • コメント

    新規な機能性材料を開発しています。特に、触媒、センサー、表示・記憶素子等の開発につながる光、温度、酸素などの「環境に応答する分子」を開発しています。

研究者情報

学位

  • 博士(工学)（近畿大学）

ホームページURL

J-Global ID

研究キーワード

  • 結晶相反応   有機金属錯体   光機能性化合物   

現在の研究分野（キーワード）

    新規な機能性材料を開発しています。特に、触媒、センサー、表示・記憶素子等の開発につながる光、温度、酸素などの「環境に応答する分子」を開発しています。

研究分野

  • ものづくり技術（機械・電気電子・化学工学） / 電子デバイス、電子機器
  • ナノテク・材料 / 機能物性化学
  • ナノテク・材料 / 無機・錯体化学

経歴

  • 2023年04月 - 現在  近畿大学理工学部 エネルギー物質学科教授
  • 2016年04月 - 2023年03月  近畿大学理工学部 応用化学科/エネルギー物質学科准教授
  • 2010年10月 - 2016年03月  九州大学大学院工学研究院 応用化学部門准教授
  • 2004年04月 - 2010年09月  金沢大学理工研究域 物質化学系助教
  • 2003年10月 - 2004年03月  大阪大学大学院博士研究員
  • 2002年02月 - 2003年09月  米国カリフォルニア大学サンディエゴ校博士研究員
  • 2000年04月 - 2002年01月  岡崎国立共同研究機構博士研究員

学歴

  •         - 2000年03月   近畿大学   工学研究科   応用化学専攻
  •         - 1995年03月   近畿大学   理工学部   応用化学科

所属学協会

  • 日本化学会 有機結晶部会   複合系の光機能研究会   錯体化学会   日本化学会   The Chemical Society of Japan   Division of the Organic Crystals   Photofunctional Chemistry of Complex Systems   

研究活動情報

論文

  • Seiji Ogo; Takeshi Yatabe; Keishi Miyazawa; Yunosuke Hashimoto; Chiaki Takahashi; Hidetaka Nakai; Yoshihito Shiota
    JACS Au 2024年03月
  • Chiaki Takahashi; Takeshi Yatabe; Hidetaka Nakai; Seiji Ogo
    Chemistry – A European Journal 29 69 2023年10月 
    Abstract Chemists have long sought to regulate the reactivity of H2, to yield hydride ions, hydrogen atoms, or electrons on demand. One source of inspiration for achieving this control is [NiFe]hydrogenase ([NiFe]H2ase), which reacts with H2 to form various hydrogen active species such as NiIII hydride species, NiII hydride species, and NiI low‐valent species. Chemists have attempted to synthesize these hydrogen active species not only as models for the active species of [NiFe]H2ase, but also as electron transfer catalysts. However, the synthesis of NiI complex directly from H2 has not been reported. This paper reports the first example of a single‐step synthesis of a NiI complex, via reaction of a NiII complex with H2, stable for over 3 months at room temperature and we further demonstrate a reductive coupling of acridinium ions as part of a reaction cycle.
  • Daiki Shimauchi; Takeshi Yatabe; Yuka Ikesue; Yuu Kajiwara; Taro Koide; Tatsuya Ando; Ki-Seok Yoon; Hidetaka Nakai; Seiji Ogo
    Chemical Communications 2023年 
    An H2-derived energy carrier that stores electrons from H2 at room temperature and transfers them to CO2 at leisure at room temperature.
  • Seiji Ogo; Takeshi Yatabe; Hidetaka Nakai
    Coordination Chemistry Reviews 470 214697 - 214697 2022年11月 [査読有り]
     
    In this review, we discuss whether the ligand design used in catalysts mimicking O2-tolerant [NiFe]hydrogenase ([NiFe]H2ase) can be applied to ligand design in catalysts for C–C bond forming reactions. First, we begin with a discussion of ligand design in catalysts that allow reductive activation of O2 by H2, using an O2-tolerant [NiFe]H2ase model catalyst. Next, we discuss whether this ligand design method- ology can be applied to reductive C–C coupling and C–H arylation reactions. Finally, we summarize the ligand design in the catalysts for reductive C–C coupling and C–H arylation reactions.
  • Yuu Kajiwara; Hikaru Yoshimizu; Kodai Matsumoto; Hidetaka Nakai
    Chemistry Letters 51 4 372 - 374 2022年04月 [査読有り]
     
    Rod-like millimeter-size crystal (2.0 mm (length) x 13 μm (width) x 31 μm (depth)) of a newly prepared photochoromic rhodium dithionite complex with n-methoxybutyl moieties shows the bending and unbending upon photoirradiation from the same side of the crystal; the bending mechanism was clarified by single crystal X-ray diffraction experiments.
  • Yuu Kajiwara; Hidetaka Nakai
    CrystEngComm 24 7 1437 - 1441 2022年02月 [査読有り]
     
    The crystalline-state photochromism of 1MPro in the β-crystal was successfully disclosed by time-dependent X-ray diffraction experiments.
  • Yuu Kajiwara; Hidetaka Nakai
    Bulletin of the Chemical Society of Japan 95 1 169 - 174 2022年01月 [査読有り]
  • Shogo Yagura; Naoki Hayakawa; Airi Kuroda; Kei Ota; Rhota Tanishita; Genya Urasaki; Tsukasa Nakahodo; Hidetaka Nakai; Manabu Hoshino; Daisuke Hashizume; Tsukasa Matsuo
    Dalton Transactions 51 48 18633 - 18641 2022年 [査読有り]
     
    We present the synthesis, structural features and absorption properties of a series of (E)-1,2-diaryldigermenes supported by the fused-ring bulky Eind groups.
  • Yuu Kajiwara; Seiya Miyata; Hidetaka Nakai
    Dalton Transactions 51 1 48 - 52 2022年 [査読有り]
     
    A reversible conformational change of an n-methoxypropyl moiety during the course of thermal back reactions was observed by time-dependent X-ray diffraction experiments.
  • Takeshi Yatabe; Tamon Tome; Yukina Takahashi; Takahiro Matsumoto; Ki‐Seok Yoon; Hidetaka Nakai; Seiji Ogo
    Chemistry – A European Journal 27 69 17326 - 17330 2021年12月 [査読有り]
  • Takeshi Yatabe; Sayaka Futakuchi; Keishi Miyazawa; Daiki Shimauchi; Yukina Takahashi; Ki-Seok Yoon; Hidetaka Nakai; Seiji Ogo
    RSC Advances 11 62 39450 - 39454 2021年12月 [査読有り]
     
    Four requirements for the reductive C(sp3)–C(sp3) homo-coupling of benzyl/allyl halides in aqueous solution by using H2 as an electron source are described.
  • Ryoma Ohno; Yasuyuki Numata; Shigeaki Konaka; Shogo Yagura; Airi Kuroda; Mao Harada; Naoko Fujita; Naoki Hayakawa; Hidetaka Nakai; Alfredo Rosas-Sánchez; Daisuke Hashizume; Tsukasa Matsuo
    Bulletin of the Chemical Society of Japan 94 7 1931 - 1939 2021年07月 [査読有り]
  • Hidetaka Nakai; Yuu Kajiwara; Seiya Miyata
    CRYSTENGCOMM 23 21 3790 - 3793 2021年06月 [査読有り]
     
    Crystalline-state photoreaction of a newly prepared organorhodium dithionite complex with n-hexyltetramethyl-cyclopentadienyl (Cp-Hex: eta(5)-C(5)Me(4)n-Hexyl) ligands was studied by single crystal X-ray diffraction experiments; 2 pi/5 rotation of the Cp-Hex ligand is induced by the photoisomerization of the dithionite group (mu-O2SSO2).
  • Hidetaka Nakai; Seiya Miyata; Yuu Kajiwara; Yoshiki Ozawa; Masaaki Abe
    DALTON TRANSACTIONS 49 6 1721 - 1725 2020年02月 [査読有り]
     
    Crystalline-state photochromism of a rhodium dithionite complex with n-propyl moieties was studied directly by performing single crystal X-ray diffraction experiments; a non-linear relationship between the degree of the conformational change of the n-propyl moiety and the degree of the photochromic reaction of the dithionite group (mu-O2SSO2) was observed at -173 degrees C.
  • Naoki Hayakawa; Tomohiro Sugahara; Yasuyuki Numata; Hotaka Kawaai; Kenta Yamatani; Shogo Nishimura; Shun Goda; Yuko Suzuki; Tomoharu Tanikawa; Hidetaka Nakai; Daisuke Hashizume; Takahiro Sasamori; Norihiro Tokitoh; Tsukasa Matsuo
    Dalton Transactions 47 3 814 - 822 2018年01月 [査読有り]
     

    We present the transformation of low-coordinate germanium(ii) compounds.

  • Hidetaka Nakai; Masafumi Kuyama; Juncheol Seo; Takahiro Goto; Takahiro Matsumoto; Seiji Ogo
    DALTON TRANSACTIONS 46 28 9126 - 9130 2017年07月 [査読有り]
     
    Taking advantage of the outstanding oxygen-sensitive luminescence properties of the previously synthesised Tb(III) complex [{((ArO)-Ar-MeMe)(3)tacn}Ln(III)(THF)] (1(Tb), Ln = Tb), herein, we have prepared an oxygen sensor based on 1(Tb) embedded in polystyrene film (1(Tb)/PS) and found that 1(Tb)/PS shows the highest sensitivity (I-0/I-100 = 14.9) and the fastest response (response/recovery time = 1.9 s/2.9 s), among the lanthanide(III)-based oxygen sensors with f-f emission. Moreover, we have prepared the lanthanide(III)-based colorimetric luminescent oxygen sensor (1(TbSm)/PS) with green-yellow-red responses, by using 1(Tb) and a newly synthesised oxygen-insensitive Sm(III) complex (1(Sm), Ln = Sm; Phi = 0.010 and tau = 12.2 mu s).
  • Koji Yoshimoto; Takeshi Yatabe; Takahiro Matsumoto; Viet-Ha Tran; Andrew Robertson; Hidetaka Nakai; Koichiro Asazawa; Hirohisa Tanaka; Seiji Ogo
    DALTON TRANSACTIONS 45 37 14620 - 14627 2016年10月 [査読有り]
     
    We report the first example of a wholly inorganic mimic of a part of the FeMoco active centre of nitrogenases. We detail the synthesis, characterisation and reactivity of two related, transient hydride-containing inorganic clusters, a dihydride complex and a vinyl monohydride complex, which bear the [Fe2MoOS3] portion of FeMoco. The dihydride complex is capable of reducing acetylene to ethylene via the vinyl monohydride complex. In the reaction cycle, a transient low-valent complex was generated by the reductive elimination of H-2 or ethylene from dihydride or vinyl monohydride complexes, respectively.
  • Hidetaka Nakai; Kazuhiro Kitagawa; Juncheol Seo; Takahiro Matsumoto; Seiji Ogo
    DALTON TRANSACTIONS 45 29 11620 - 11623 2016年08月 [査読有り]
     
    This paper presents a gadolinium(III) complex that shows blue phosphorescence in the crystalline state at room temperature under air atmosphere; color of the crystals can be changed to pale-green from blue by doping of 1-naphthol.
  • Hidetaka Nakai; Juncheol Seo; Kazuhiro Kitagawa; Takahiro Goto; Kyoshiro Nonaka; Takahiro Matsumoto; Seiji Ogo
    INORGANIC CHEMISTRY 55 13 6609 - 6615 2016年07月 [査読有り]
     
    Coordination environment of the Tb3+ ion in oxygen-sensitive luminescent complexes can be successfully controlled through the size of alkyl substituents on ligands {((ArOH)-Ar-Rme)(4)cyclen} (R = tBu or Me; cyclen = 1,4,7,10-tetraazacyclododecane); a newly prepared eight-coordinate complex 1(tBu) shows higher oxygen sensitivity (K-SV = 17 600) and lower luminescence quantum yield (Phi = 0.67 under N-2) = than those of the previously reported seven-coordinate analogues 1(Me) and [{((ArO)-Ar-MeMe)(3)tacn}Tb-III(THF)] (K-SV = 12 600 and 8300, Phi = 0.91 and 0.91 under N-2, respectively; tacn = 1,4,7-triazacyclononane; THF = tetrahydrofuran). The oxygen-sensitive mechanism is discussed on the basis of the photophysical properties of the corresponding Gd(III) complexes.
  • Hidetaka Nakai; Juncheol Seo; Kazuhiro Kitagawa; Takahiro Goto; Takahiro Matsumoto; Seiji Ogo
    DALTON TRANSACTIONS 45 23 9492 - 9496 2016年06月 [査読有り]
     
    This paper presents the first dysprosium(III) complex, [{((ArO)-Ar-MeMe)(3)tacn}Dy-III(THF)] (1(Dy)), that shows oxygen-sensitive luminescence. The synthesis, structure and oxygen-sensitive luminescence properties of 1(Dy) are reported (Phi = 0.050 and tau = 17.7 mu s under N-2, Phi = 0.011 and tau = 4.1 mu s under O-2 and K-SV = 305 M-1 in THF; K-SV = 0.0077%(-1) in polystyrene film). The oxygen sensitive mechanism of 1(Dy) is discussed based on the photophysical properties of the corresponding gadolinium(III) complex, [{((ArO)-Ar-MeMe)(3)tacn} Gd-III(THF)].
  • Hidetaka Nakai; Kengo Matsuba; Masataka Akimoto; Tomonori Nozaki; Takahiro Matsumoto; Kiyoshi Isobe; Masahiro Irie; Seiji Ogo
    CHEMICAL COMMUNICATIONS 52 23 4349 - 4352 2016年03月 [査読有り]
     
    Rod-like millimetre-size crystals of a newly prepared rhodium dithionite complex with n-pentyl moieties bend upon photoirradiation and return to the initial shape upon heating; the roles of the flexible n-pentyl moieties as well as the photoreactive dithionite unit (mu-O2SSO2) are disclosed by single crystal X-ray diffraction.
  • Yoshimoto Koji; Yatabe Takeshi; Matsumoto Takahiro; Robertson Andrew; Nakai Hidetaka; Tanaka Hiromasa; Kamachi Takashi; Shiota Yoshihito; Yoshizawa Kazunari; Asazawa Koichiro; Tanaka Hirohisa; Ogo Seiji
    Chemistry Letters 45 2 149 - 151 公益社団法人 日本化学会 2016年02月 [査読有り]
     
    We report the first example of a µ-η1:η1-N2 dinuclear RuII complex with a polyamine ligand and elucidate the structure by means of X-ray analysis. The N≡N stretching vibration has been observed at 1994 cm−1 by Raman spectroscopy, which is the lowest value of all the known N2-coordinated RuII complexes. This low value strongly suggests the N≡N bond is primed for activation.
  • Matsumoto Takahiro; Yoshimoto Koji; Zheng Chunbai; Shomura Yasuhito; Higuchi Yoshiki; Nakai Hidetaka; Ogo Seiji
    Chemistry Letters 45 2 197 - 199 公益社団法人 日本化学会 2016年02月 [査読有り]
     
    We report the synthesis, characterization, and reactivity of a NiRu monohydride complex with a pyridine-bound hexamethylbenzene ligand. We investigate the mechanistic insights it provides on the H2-activation of [NiFe]hydrogenase.
  • Takashita Keisuke; Matsumoto Takahiro; Yatabe Takeshi; Nakai Hidetaka; Ogo Seiji
    Chemistry Letters 45 2 137 - 139 公益社団法人 日本化学会 2016年02月 [査読有り]
     
    We report the first example of a non-precious metal molecular catalyst for a fuel cell cathode. A nickel dihydrido complex is capable of reducing dioxygen to water through a four-electron pathway, as evidenced by an isotope-labeling experiment and electrochemical measurements.
  • Takahiro Kishima; Takahiro Matsumoto; Hidetaka Nakai; Shinya Hayami; Takehiro Ohta; Seiji Ogo
    ANGEWANDTE CHEMIE-INTERNATIONAL EDITION 55 2 724 - 727 2016年01月 [査読有り]
     
    Dioxygen-tolerant [NiFe] hydrogenases catalyze not only the conversion of H-2 into 2H(+) and 2e(-) but also the reduction of O-2 to H2O. Chemists have sought to mimic such bifunctional catalysts with structurally simpler compounds to facilitate analysis and improvement. Herein, we report a new [NiFe]-based catalyst for O-2 reduction via an O-2 adduct. Structural investigations reveal the first example of a side-on iron(IV) peroxo complex.
  • Keisuke Takashita; Takahiro Matsumoto; Takeshi Yatabe; Hidetaka Nakai; Masatatsu Suzuki; Seiji Ogo
    Chemistry Letters 45 1 72 - 74 2016年01月 [査読有り]
  • Takahiro Matsumoto; Tatsuya Ando; Yuki Mori; Takeshi Yatabe; Hidetaka Nakai; Seiji Ogo
    Journal of Organometallic Chemistry 796 73 - 76 2015年11月 [査読有り]
  • Takeshi Yatabe; Mitsuhiro Kikkawa; Takahiro Matsumoto; Keishi Urabe; Andrew Robertson; Hidetaka Nakai; Seiji Ogo
    Chemistry Letters 44 9 1263 - 1265 2015年09月 [査読有り]
  • Viet-Ha Tran; Takeshi Yatabe; Takahiro Matsumoto; Hidetaka Nakai; Kazuharu Suzuki; Takao Enomoto; Takashi Hibino; Kenji Kaneko; Seiji Ogo
    CHEMICAL COMMUNICATIONS 51 63 12589 - 12592 2015年08月 [査読有り]
     
    We report an acid-stable Si oxide-doped Ir oxide film (IrSi oxide film), made by metal organic chemical vapour deposition (MOCVD) of an Ir-V complex for electrochemical water-oxidation. This is a successful improvement of catalytic ability and stability depending upon the pH of Ir oxide by doping of Si oxide. The turnover frequency (TOF) of the electrochemical water-oxidation by the IrSi oxide film is the highest of any Si oxide-doped Ir oxide materials and higher even than that of Ir oxide in acidic media.
  • Hidetaka Nakai; Kyoshiro Nonaka; Takahiro Goto; Juncheol Seo; Takahiro Matsumoto; Seiji Ogo
    DALTON TRANSACTIONS 44 24 10923 - 10927 2015年06月 [査読有り]
     
    This paper presents a 1,4,7,10-teraazacyclododecane-based tetrakis-phenol as a protonated ligand precursor and its oxygen-sensitive luminescent terbium(III) complex with an extendable phenol pendant arm (Phi = 0.91 under N-2, Phi = 0.031 under air), in which the potentially N4O4-octadentate ligand unprecedentedly coordinates to the Tb3+ ion in a N4O3-heptadentate fashion.
  • Tran Viet-Ha; Yatabe Takeshi; Matsumoto Takahiro; Nakai Hidetaka; Suzuki Kazuharu; Enomoto Takao; Ogo Seiji
    Chemistry Letters 44 6 794 - 796 The Chemical Society of Japan 2015年06月 [査読有り]
     
    We report the first example of a Ni0 precursor that provides a contamination-free (<1%) nickel film by metal–organic chemical vapor deposition (MOCVD) using N2 as the carrier gas. The structure and physical properties of the Ni0 precursor and subsequent film are described.
  • Hidetaka Nakai; Takahiro Goto; Kazuhiro Kitagawa; Kyoshiro Nonaka; Takahiro Matsumoto; Seiji Ogo
    CHEMICAL COMMUNICATIONS 50 99 15737 - 15739 2014年12月 [査読有り]
     
    This communication presents a new terbium(III) complex that shows the highest luminescence quantumyield among the oxygen-sensitive lanthanide complexes (Phi = 0.91 under N-2, Phi = 0.054 under air).
  • Nga T. Nguyen; Yuki Mori; Takahiro Matsumoto; Takeshi Yatabe; Ryota Kabe; Hidetaka Nakai; Ki-Seok Yoon; Seiji Ogo
    CHEMICAL COMMUNICATIONS 50 87 13385 - 13387 2014年11月 [査読有り]
     
    We report the decomposition of formic acid to hydrogen and carbon dioxide, catalysed by a NiRu complex originally developed as a [NiFe]hydrogenase model. This is the first example of H-2 evolution, catalysed by a [NiFe]hydrogenase model, which does not require additional energy.
  • Harutaka Nakamori; Takahiro Matsumoto; Takeshi Yatabe; Ki-Seok Yoon; Hidetaka Nakai; Seiji Ogo
    CHEMICAL COMMUNICATIONS 50 86 13059 - 13061 2014年11月 [査読有り]
     
    Herein, we report the first crystal structure of a monomeric p-semiquinonato d-block complex and its reactivity toward dioxygen, closely associated with a biological system of an oxygen evolving centre of photosystem II.
  • Nakai H; Jeong K; Matsumoto T; Ogo S
    Organometallics 33 17 4349 - 4352 2014年09月 [査読有り]
     
    A new class of efficient catalyst, the Rh(I) complex [(eta(5)-C5Me5)Rh-I(bpy)] (1; bpy = 2,2'-bipyridine), for the C-F bond hydrogenolysis of fluoroaromatics (C6F5CF3, C6F6, C6F5H, and C6F5CH3) is presented. The best turnover number of 380 for C6F6 is afforded by using 0.1 mol % of 1, 0.8 MPa of H-2, and 2 equiv of Et2NH in CH3CN at 25 degrees C. The successful isolation of the C-F bond cleavage product [(eta(5)-C5Me5)Rh-III(bpy)(C6F5)](F) as a plausible intermediate of the catalytic hydrogenolysis of C6F6 by 1 is also described.
  • Takahiro Matsumoto; Shigenobu Eguchi; Hidetaka Nakai; Takashi Hibino; Ki-Seok Yoon; Seiji Ogo
    ANGEWANDTE CHEMIE-INTERNATIONAL EDITION 53 34 8895 - 8898 2014年08月 [査読有り]
     
    Reported herein is an electrode for dihydrogen (H-2) oxidation, and it is based on [NiFe] Hydrogenase from Citrobacter sp. S-77 ([NiFe](S77)). It has a 637 times higher mass activity than Pt (calculated based on 1 mg of [NiFe](S77) or Pt) at 50 mV in a hydrogen half-cell. The [NiFe](S77) electrode is also stable in air and, unlike Pt, can be recovered 100% after poisoning by carbon monoxide. Following characterization of the [NiFe](S77) electrode, a fuel cell comprising a [NiFe](S77) anode and Pt cathode was constructed and shown to have a a higher power density than that achievable by Pt.
  • Takeshi Yatabe; Takahiro Kikunaga; Takahiro Matsumoto; Hidetaka Nakai; Ki-Seok Yoon; Seiji Ogo
    Chemistry Letters 43 8 1380 - 1382 2014年08月 [査読有り]
  • Takeshi Yatabe; Mitsuhiro Kikkawa; Takahiro Matsumoto; Hidetaka Nakai; Kenji Kaneko; Seiji Ogo
    DALTON TRANSACTIONS 43 8 3063 - 3071 2014年02月 [査読有り]
     
    We propose a model for the water-oxidation and recovery systems of the oxygen-evolving complex (OEC) of the photosystem II (PSII) enzyme. The whole system is constructed from two catalytic cycles, conducted as a tandem reaction: (i) a water-oxidation loop uses cerium(IV) ammonium nitrate as an oxidant to activate a dimanganese complex for water-oxidation and thereby liberate a molecule of O-2 and (ii) a recovery loop begins with photoinhibition of the dimanganese complex but then uses O-2 to reactivate the manganese centre. The net result is a catalytic water-oxidation catalyst that can use self-generated O-2 for recovery.
  • Takahiro Kikunaga; Takahiro Matsumoto; Takehiro Ohta; Hidetaka Nakai; Yoshinori Naruta; Kwang-Hyun Ahn; Yoshihito Watanabe; Seiji Ogo
    CHEMICAL COMMUNICATIONS 49 75 8356 - 8358 2013年09月 [査読有り]
     
    The first example of monooxygenation by a high-valent Mn-IV complex with a peroxide is described. A key Mn-IV acylperoxo intermediate, which uses m-chloroperoxybenzoic acid as the oxygen donor, is directly observed by electro-spray ionization mass spectrometry and resonance Raman spectroscopy.
  • Hidetaka Nakai; Kazuhiro Kitagawa; Harutaka Nakamori; Taisuke Tokunaga; Takahiro Matsumoto; Koichi Nozaki; Seiji Ogo
    ANGEWANDTE CHEMIE-INTERNATIONAL EDITION 52 33 8722 - 8725 2013年08月 [査読有り]
  • Daisuke Inoki; Takahiro Matsumoto; Hidetaka Nakai; Seiji Ogo
    European Journal of Inorganic Chemistry 2013 22-23 3978 - 3986 2013年08月 [査読有り]
  • Takahiro Matsumoto; Kyoungmok Kim; Hidetaka Nakai; Takashi Hibino; Seiji Ogo
    ChemCatChem 5 6 1368 - 1373 2013年06月 [査読有り]
  • Seiji Ogo; Koji Ichikawa; Takahiro Kishima; Takahiro Matsumoto; Hidetaka Nakai; Katsuhiro Kusaka; Takashi Ohhara
    SCIENCE 339 6120 682 - 684 2013年02月 [査読有り]
     
    Chemists have long sought to mimic enzymatic hydrogen activation with structurally simpler compounds. Here, we report a functional [NiFe]-based model of [NiFe] hydrogenase enzymes. This complex heterolytically activates hydrogen to form a hydride complex that is capable of reducing substrates by either hydride ion or electron transfer. Structural investigations were performed by a range of techniques, including x-ray diffraction and neutron scattering, resulting in crystal structures and the finding that the hydrido ligand is predominantly associated with the Fe center. The ligand's hydridic character is manifested in its reactivity with strong acid to liberate H-2.
  • Kyoungmok Kim; Takahiro Kishima; Takahiro Matsumoto; Hidetaka Nakai; Seiji Ogo
    ORGANOMETALLICS 32 1 79 - 87 2013年01月 [査読有り]
     
    We present two closely related series of a [NiFe] hydrogenase analogue. Based on a [NiRu] core, these complexes demonstrate inactivity, H-2 activation, or O-2 activation depending only on the nature of the Ru-coordinated aromatic ligand. It is demonstrated that even small changes made to this aromatic ligand can modulate the catalytic activity of the complex. Structural, electrochemical, kinetic, and thermodynamic studies reveal that differences in activation and binding modes of the substrates, combined with differences in a donation and lability of the aromatic ligands, result in abrupt changes in catalytic activity.
  • Muratsugu S; Weng Z; Nakai H; Isobe K; Kushida Y; Sasaki T; Tada M
    Physical Chemistry Chemical Physics 14 46 16023 - 16031 2012年11月 [査読有り]
     
    A novel oxide-supported Ir dimer, which was found to be active for transfer hydrogenation of aromatic ketones, was prepared on a gamma-Al2O3 surface from an Ir dimer complex [Ir-2{eta(5)-C-5(CH3)(5)}(2)(mu-CH2)(2)] (Ir-2) with an Ir=Ir bond. Detailed characterization of the gamma-Al2O3-supported Ir dimer (Ir-2/gamma-Al2O3) revealed that the structure of Ir-2 consisted of an Ir dimer with an Ir-Ir bond attached to the gamma-Al2O3 surface by two bridged Ir-(OAl)(2)-Ir bonds. The supported Ir-2/gamma-Al2O3 dimer with bridged Ir-(OAl)(2)-Ir bonds acted as an efficient catalyst for transfer hydrogenation (turnover number of acetophenone = 699 (24 h)), while homogeneous Ir-2, SiO2- and MgO-supported Ir-2 were much less active. A structural transformation at the interface of the Ir dimer and the gamma-Al2O3 surface was suggested to assist the transfer hydrogenation catalysis via the formation of an Ir-2-H-2 species on the gamma-Al2O3 surface (Ir-2-H-2/gamma-Al2O3) as a key intermediate in the transfer hydrogenation. The present study deepened the understanding of the role and dynamic behaviour of the oxide surface in the hydrogen transfer catalysis on the supported Ir dimer.
  • JEONG Kihun; NAKAMORI Harutaka; IMAI Shunsuke; MATSUMOTO Takahiro; OGO Seiji; NAKAI Hidetaka
    Chemistry letters 41 6 650 - 651 2012年06月 [査読有り]
  • Oanh P. Lam; Sebastian M. Franke; Hidetaka Nakai; Frank W. Heinemann; Wolfgang Hieringer; Karsten Meyer
    INORGANIC CHEMISTRY 51 11 6190 - 6199 2012年06月 [査読有り]
     
    An inverse trans influence has been observed in a high-valent U(V) imide complex, [(((ArO)-Ar-Ad)(3)N)U(NMes)]. A thorough theoretical evaluation has been employed in order to corroborate the ITI in this unusual complex. Computations on the target complex, [(((ArO)-Ar-Ad)(3)N)U(NMes)], and the model complexes [(((ArO)-Ar-Me)(3)N)U(NMes)] and [(NMe3)(OMe2)(OMe)(3)U(NPh)] are discussed along with synthetic details and supporting spectroscopic data. Additionally, the syntheses and full characterization data of the related U(V) trimethylsilylimide complex [(((ArO)-Ar-Ad)(3)N)U(NTMS)] and U(IV) azide complex [(((ArO)-Ar-Ad)(3)N)U(N-3)] are also presented for comparison.
  • Kyoungmok Kim; Takahiro Matsumoto; Andrew Robertson; Hidetaka Nakai; Seiji Ogo
    CHEMISTRY-AN ASIAN JOURNAL 7 6 1394 - 1400 2012年06月 [査読有り]
     
    Herein, we report a [NiRu] biomimetic system for O2-tolerant [NiFe]hydrogenases and demonstrate that electron donation to the [NiRu] center can switch the system between the activation of H2 and O2 through simple ligand effects by using hexamethylbenzene and pentamethylcyclopentadienyl ligands, respectively. Furthermore, we present the synthesis and direct observations of a [NiRu]peroxo species, which was formed by the oxygenation of a Ni-SIa model [NiRu] complex, that we propose as a biomimetic analogue of O2-bound species (OBS) of O2-tolerant [NiFe]hydrogenases. The [NiRu]peroxo complex was fully characterized by X-ray analysis, X-ray photoelectron spectroscopy (XPS), mass spectrometry, and 1H NMR spectroscopy. The OBS analogue was capable of oxidizing p-hydroquinone and sodium borohydride to turn back into the Ni-SIa model complex.
  • Daisuke Inoki; Takahiro Matsumoto; Hidetaka Nakai; Seiji Ogo
    ORGANOMETALLICS 31 8 2996 - 3001 2012年04月 [査読有り]
     
    A Rh-III monohydride terpyridine complex undergoes reductive elimination of H-2 in CH3CN to form a dinuclear Rh-II complex with a metal-metal bond. Kinetic studies have revealed that the conversion from the monohydride species to the dinuclear species with evolution of H-2 obeys first-order kinetics and have determined the kinetic deuterium isotope effect value to be 2.0. We discuss the mechanism for the reductive elimination of H-2 from rhodium hydride species.
  • Daisuke Inoki; Takahiro Matsumoto; Hideki Hayashi; Keisuke Takashita; Hidetaka Nakai; Seiji Ogo
    DALTON TRANSACTIONS 41 15 4328 - 4334 2012年04月 [査読有り]
     
    Reductive activation of O-2 by H-2 with rhodium terpyridine complexes in H2O and CH3CN is described and the mechanism is fully elucidated. The rhodium complex extracts electrons from H-2 and reductively activates O-2 to form a peroxo active intermediate. This intermediate is able to oxidise triphenyl phosphine to triphenyl phosphine oxide. A model system constructed in CH3CN provides isolable analogues of catalytic intermediates in H2O, allowing a detailed look at each step in the catalytic cycle.
  • Daisuke Inoki; Takahiro Matsumoto; Hidetaka Nakai; Seiji Ogo
    CHEMISTRY LETTERS 41 1 116 - 118 2012年01月 [査読有り]
     
    We report the synthesis of a mer-triaqua Rh-III complex using terpyridine as a meridional tridentate ligand. This is the first example of a structurally characterized six-coordinated mer-triaqua complex for any second- or third-row element from the main transition-metal groups (groups 5-11). This is also the first example of a structurally characterized mer-triaqua complex with terpyridine for any transition metal. Acid dissociation constants, pK(a1) and pK(a2), of the triaqua complex are determined to be 3.0 and 6.9, respectively.
  • Takeshi Yatabe; Masaki Karasawa; Kiyoshi Isobe; Seiji Ogo; Hidetaka Nakai
    DALTON TRANSACTIONS 41 2 354 - 356 2012年01月 [査読有り]
     
    A naphthyl-substituted pentamethylcyclopentadienyl ligand (Cp-Naph = eta(5)-C5Me4CH2C10H7) and its Sm(II) complexes [Sm(Cp-Naph)(2)(THF)(x)] (1: x = 2, 2: x = 0) have been prepared and characterised. The solvent-induced reversible conversion between the di-THF solvated purple complex 1 and the un-solvated dark green complex 2 is presented.
  • Takahiro Matsumoto; Ryota Kabe; Kyoshiro Nonaka; Tatsuya Ando; Ki-Seok Yoon; Hidetaka Nakai; Seiji Ogo
    INORGANIC CHEMISTRY 50 18 8902 - 8906 2011年09月 [査読有り]
     
    We propose a modified mechanism for the inhibition of [NiFe]hydrogenase ([NiFe]H(2)ase) by CO. We present a model study, using a NiRu H(2)ase mimic, that demonstrates that (i) CO completely inhibits the catalytic cycle of the model compound, (ii) CO prefers to coordinate to the Ru(II) center rather than taking an axial position on the Ni(II) center, and (iii) CO is unable to displace a hydrido ligand from the NiRu center. We combine these studies with a reevaluation of previous studies to propose that, under normal circumstances, CO inhibits [NiFe]H(2)ase by complexing to the Fe(II) center.
  • Hidetaka Nakai; Shinobu Uemura; Yousuke Miyano; Motohiro Mizuno; Masahiro Irie; Kiyoshi Isobe
    DALTON TRANSACTIONS 40 10 2177 - 2179 2011年03月 [査読有り]
     
    A photoreactive rhodium dithionite complex [(RhCp(Et))(2)(mu-CH(2)) (2)(mu-O(2)SSO(2))] (1(Et)) with Cp(Et) (eta(5)-C(5)Me(4)Et) ligands was newly synthesized. Upon short-time irradiation with low intensity light, two kinds of stepwise surface morphology changes of the crystal 1(Et) were observed. Prolonged irradiation with high intensity light caused cracking and breaking down of the crystal.
  • Hidetaka Nakai; Saori Nakano; Shunsuke Imai; Kiyoshi Isobe
    ORGANOMETALLICS 29 19 4210 - 4212 2010年10月 [査読有り]
     
    Reduction of [Cp*(2)Ir(2)(mu-CH(2))(2)Cl(2)] (Cp* = eta(5)-C(5)Me(5)) with Na in benzene leads to the formation of a methylene-bridged iridium(I) dinuclear complex with a considerably short Ir-Ir double bond (2.4375(2) angstrom), [Cp*(2)Ir(2)(mu-CH(2))(2)], which reacts with alcohols (RCH(2)OH, R = H, Me, Et, Ph) to afford a unique cis-dihydride complex and the respective aldehyde (RCHO).
  • Takeshi Yatabe; Hidetaka Nakai; Koichi Nozaki; Tomoo Yamamura; Kiyoshi Isobe
    ORGANOMETALLICS 29 11 2390 - 2393 2010年06月 [査読有り]
     
    Lanthanide(III)bent-metallocene complexes with a novel photofunctionalized pentamethylcyclopentadienyl ligand having an N-phenylcarbazolyl group (Cp-PhCar = eta(5)-C5Me4CH2-C18H12N), [Ln(Cp-PhCar)(2)I(THF)] (Ln = Tb (1), Gd (2)), were prepared and their molecular structures and luminescence properties were investigated. The f-f emission from the terbium metal center of I was efficiently sensitized by Cp-PhCar (epsilon = 0.88 x 10(4) M-1 cm(-1) at 331 nm, Phi = 0.67 at 330 nm excitation, k(r) = 1.68 x 10(3) s(-1)). Additionally, the solid-state structure of potassium salts of C-5-ring (eta(5)-C5R5, R = Me, H) derivatives was uncommonly characterized in Cp-PhCar.
  • Hidetaka Nakai; Mayu Hatake; Yousuke Miyano; Kiyoshi Isobe
    CHEMICAL COMMUNICATIONS 19 2685 - 2687 2009年 [査読有り]
     
    An achiral photochromic dithionite (mu-O(2)SSO(2)) complex with n-propyl moieties forms chiral crystals and undergoes an enantioselective photoisomerization (ee > 90%) to an oxysulfur (mu-O(2)SOS*O) complex, containing an asymmetric S atom, with essentially 100% interconversion of the chiral crystals.
  • Hidetaka Nakai; Takashi Nonaka; Yousuke Miyano; Motohiro Mizuno; Yoshiki Ozawa; Koshiro Toriumi; Nobuaki Koga; Takanori Nishioka; Masahiro Irie; Kiyoshi Isobe
    JOURNAL OF THE AMERICAN CHEMICAL SOCIETY 130 52 17836 - 17845 2008年12月 [査読有り]
     
    In the crystalline state, the rhodium dinuclear complex [(RhCp*)(2)(mu-CH(2))(2)(mu-O(2)SSO(2))] (1) with a photoresponsive dithionite group (mu-O(2)SSO(2)) and two pentamethylcyclopentadienyl ligands (Cp* = eta(5)-C(5)Me(5)) undergoes a 100% reversible unimolecular type T inverse photochromism upon interconversion to [(RhCp*)(2)(mu-CH(2))(mu-O(2)SOSO)] (2). The photochromism can be followed directly by using stepwise crystal structure analysis (Angew. Chem., Int Ed. 2006, 45, 6473). In this study, we found that the photoreaction of 1 was triggered by absorption of the 510 nm light (charge transfer band from sigma(S-S) to sigma*(S-S) and e(Rh-Rh) orbitals assigned by DFT calculation) and included two important processes: kinetically controlled oxygen-atom transfer to produce four stereoisomers of 2 and thermodynamically controlled isomerization between the four stereoisomers of 2 to afford the most stable isomer. Although the formation rate of the four stereoisomer products was kinetically controlled and the population of the four stereoisomers produced in the system was thermodynamically controlled, both processes were regulated by the steric hindrance between the mu-O(2)SSO(2) or mu-O(2)SOSO ligand and the reaction cavity formed by the Cp* ligands. The cooperation of both processes achieved an intriguing stereospecific oxygen-atom rearrangement to produce only one stereoisomer of 2 at the final stage of the photoreaction at room temperature. We also determined the effect of the oxygen-atom rearrangement on the rotational motion of the two crystallographically independent Cp* ligands (parallel and perpendicular arrangement). Using variable-temperature (13)C CP/MAS NMR and quadrupolar echo solid-state (2)H NMR spectroscopies, before photoirradiation, the activation energies for the rotation of the parallel and perpendicular Cp* ligands in 1 were determined to be 33 +/- 3 and 7.8 +/- 1 kJ/mol, respectively, and after photoirradiation, in 2, they were much lower than those in 1 (21 +/- 2 and 4.7 +/- 0.5 kJ/mol, respectively). The large decrease in the activation energy for the parallel Cp* in 2 is attributed to the relaxation of molecular stress via a stereospecific oxygen-atom rearrangement, which suggests that the rotational motion of the Cp* ligands is coupled to the photochromism.
  • Yousuke Miyano; Hidetaka Nakai; Motohiro Mizuno; Kiyoshi Isobe
    CHEMISTRY LETTERS 37 8 826 - 827 2008年08月 [査読有り]
     
    Crystalline-state photoisomerization of a rhodium dithionite complex with benzyltetramethylcyclopentadienyl ligand, [((CpRh)-Rh-Bn)(2)(mu-CH2)(2)(mu-O2SSO2)] (Cp-Bn = eta(5)-C5Me4Bn), is studied by X-ray crystallography and CP/MAS C-13 NMR spectroscopy. The disorder of the Cp-Bn ring in the crystal and the crystal packing of the molecules of isomers produced by photoreaction play an important role for stabilization of the whole crystal.
  • Miyano Y; Nakai H; Hayashi Y; Isobe K
    Journal of Organometallic Chemistry 692 1-3 122 - 128 2007年01月 [査読有り]
     
    A photoresponsive rhodium dinuclear complex having phenyltetramethylcyclopentadienyl (Cp-Ph = eta(5)-C5Me4Ph) and photosensitive dithionite (mu-O2SSO2) ligands, [((CpRh)-Rh-Ph)(2)(mu-CH2)(2)(mu-O2SSO2)] (1), has been synthesized. The crystal of complex 1 (monoclinic, C2/m (No. 12), a = 24.805(2) angstrom, b = 29.111(2) angstrom, c = 10.8475(11) angstrom, beta = 105.9830(7)degrees, V = 7530.0(12) angstrom(3), Z = 8) consists of two independent molecules, 1-cis and 1-trans, with different arrangement of the CpPh ligands. The flexibility, volume, and shape of the reaction cavities around the dithionite unit of 1-cis and 1-trans in the crystal are discussed. The crystal structures of the precursors of 1, trans[((CpRh)-Rh-Ph)(2)(mu-Cl)(2)Cl-2] and trans-[((CpRh)-Rh-Ph)(2)(mu-CH2)(2)Me-2], are also reported. (c) 2006 Elsevier B.V. All rights reserved.
  • Hidetaka Nakai; Motohiro Mizuno; Takanori Nishioka; Nobuaki Koga; Kimie Shiomi; Yousuke Miyano; Masahiro Irie; Brian K. Breedlove; Isamu Kinoshita; Yoshihito Hayashi; Yoshiki Ozawa; Takae Yonezawa; Koshiro Toriumi; Kiyoshi Isobe
    ANGEWANDTE CHEMIE-INTERNATIONAL EDITION 45 39 6473 - 6476 2006年10月 [査読有り]
  • Castro-Rodriguez, I; H Nakai; K Meyer
    ANGEWANDTE CHEMIE-INTERNATIONAL EDITION 45 15 2389 - 2392 2006年04月 [査読有り]
  • S Ogo; Y Takebe; K Uehara; T Yamazaki; H Nakai; Y Watanabe; S Fukuzumi
    ORGANOMETALLICS 25 2 331 - 338 2006年01月 [査読有り]
     
    The series of water-soluble palladacyclic aqua complexes [('Bu-SCS)Pd-II(H2O)](+) ([1](+), 'Bu-SCS = C6H3-2,6-(CH2S'Bu)(2)), [(Pr-i-SCS)Pd-II(H2O)](+) ([2](+), Pr-i-SCS = C6H3-2,6-((CH2SPr)-Pr-i)(2)), [(PCP)Pd-II(H2O)](+) ([3](+), PCP = C6H3-2,6-((OPPr2)-Pr-i)(2)), and [(PC)Pd-II(H2O)(2)](+) ([4](+), PC = 4-MeC6H3-2-((OPPr2)-Pr-i)) have been synthesized from the reaction of the corresponding palladacyclic chloro complexes with silver salts in water to optimize the catalytic activity for pH-dependent C-C coupling reactions in water by changing the supporting ligands from S-supporting (SCS) to P-supporting (PCP) ligands and also from tridentate (PCP) to bidentate (PC) ligands. It was confirmed that there was no precipitation of palladium black L under the present reaction conditions. The PC palladacyclic aqua complex [4](+) exhibits the highest catalytic activity among the water-soluble palladacyclic aqua complexes [1](+)-[4](+) for the pH-dependent Suzuki-Miyaura, Mizoroki-Heck, and Stille coupling reactions in water. This is one of the highest catalytic activities ever reported for coupling reactions with water-soluble palladium catalysts in water. The catalytic ability of the palladacyclic aqua catalysts is drastically dependent on the pH of the solution and the structures of supporting ligands. The structures of palladacyclic aqua and chloro complexes were unequivocally determined by X-ray analysis.
  • SATAKE Yuh; NAKAI Hidetaka; ITO Seishiro; FUJIHARA Hisashi
    Journal of the Japan Society of Colour Material 78 11 507 - 513 一般社団法人 色材協会 2005年11月 [査読有り]
     
    Redox-active gold nanoparticles containing tetrathiafulvalene as an electron donor (TTF-Au nanoparticles) and fullerene C<SUB>60</SUB> as an electron acceptor (C<SUB>60</SUB>-Au nanoparticles) have been prepared by the reaction of octanethiol-stabilized gold nanoparticles with a tetrathiafulvalenyl-monothiol and a fullerene C<SUB>60</SUB>-terminated alkanethiol. Immersion of a gold electrode in a solution of the colloidal TTF-Au nanoparticles deposited the colloid films of them on the electrode surface, which were remarkably stable under repeated electrochemical cycling. Analogously, the self-assembly of C<SUB>60</SUB>-Au on planar gold surface led to the formation of the nanoparticle films which showed two distinct reversible reduction/oxidation waves and significant electrochemical stability. The electrochemical responses for the C<SUB>60</SUB>-Au nanoparticle films and self-assembled monolayers of the C<SUB>60</SUB>-thiol adsorbed on gold electrodes are significantly different. The nanocomposite films containing electron-donor and -acceptor functions such as TTF-Au and C<SUB>60</SUB>-Au can be characterized by cyclic voltammetry.
  • B Kure; S Ogo; D Inoki; H Nakai; K Isobe; S Fukuzumi
    JOURNAL OF THE AMERICAN CHEMICAL SOCIETY 127 41 14366 - 14374 2005年10月 [査読有り]
     
    An open capsule-type octanuclear heterometallic sulfide cluster without an intramolecular inversion center [Ru(eta(6)-C6Me6){P(OMe)(3)},{MoO(mu(3)-S)(3)}(Cul)(2)}(2) (5) has been synthesized for the first time by stepwise connection of three mononuclear building blocks, i.e., (i) [RuCl2(eta(6)-C6Me6){P(OMe)(3)}] (1a) as an octahedral terminal building block to control the direction of cluster expansion, (ii) [MoOS3](2-) as a tetrahedral polydentate building block owing to the strong coordination ability of the S atoms, and (iii) a Cul building block to form a trigonal planar (mu-S)(2)Cul unit or to form a linkage unit of two incomplete cubane-type octanuclear frameworks. The stepwise connection was made in the following order: [RuCl2(eta(6)-C6Me6){P(OMe)(3)}] (1a, mononuclear) -> [Ru(eta(6)-C6Me6){P(OMe)(3)},{MoOS(mu(2)-S)(2)}] (2a, dinuclear) -> [Ru(eta(6)-C6Me6){P(OMe)(3)},{MoO(mu(2)-S)(2)(mu(3)-S)}Cul] (3a, butterfly-type trinuclear) -> [Ru(eta(6)-C6Me6){P(OMe)(3)},{MoO(mu(3)-S)(3)}(Cul)(2)](2) (5). When P(OMe)(3) was replaced by P(OEt)(3), which is more bulky than P(OMe)(3), in the starting ruthenium building block [RuCl2(eta(6)-C6Me6){P(OEt)(3))] (1b, mononuclear), only the tetranuclear incomplete single cubane cluster [Ru(eta(6)-C6Me6){P(OEt)(3)},{MoO(mu(3)-S)(3)}(Cul)(2)] (6) was generated, owing to the steric effect of P(OEt)(3).
  • SA Cortes; MAM Hernandez; H Nakai; Castro-Rodriguez, I; K Meyer; AR Fout; DL Miller; JC Huffman; DJ Mindiola
    INORGANIC CHEMISTRY COMMUNICATIONS 8 10 903 - 907 2005年10月 [査読有り]
     
    A family of neutral and cationic Ti(IV) complexes supported by the sterically demanding and trianionic ligand (O3N)(3-)(O3N3-(O3N3- = tris(2-0,3-Ad,5-tBubenzyl)amine, Ad = 1-adamantyl) have been prepared from the hydrolysis of TiCl4(THF)(2) with the free base (O3N)H-3 and excess NEt3, followed by anion exchange reactions. These (O3N)Ti+ cores are resistant to moisture and air, are mononuclear, and possess C-3 symmetry on the NMR timescale. (c) 2005 Elsevier B.V. All rights reserved.
  • Castro-Rodriguez I; Nakai H; Zakharov L.N; Rheingold A.L; Meyer K
    Science 305 5691 1757 - 1759 2004年09月 [査読有り]
     
    The electron-rich, six-coordinate tris-aryloxide uranium(III) complex [(((ArO)-Ar-Ad)(3)tacn)U-III] [where ((ArOH)-Ar-Ad)(3)tacn = 1,4,7-tris(3-adamantyl-5-tert-butyl-2-hydroxybenzyl)-1,4,7-triazacyclononane] reacts rapidly with CO, to yield [(((ArO)-Ar-Ad)(3)tacn)U-IV(CO2)], a complex in which the CO2 ligand is linearly coordinated to the metal through its oxygen atom (eta(1)-OCO). The latter complex has been crystallographically and spectroscopically characterized. The inequivalent O-C-O bond lengths [1.122 angstroms (Angstrom) for the O-C bond adjacent to uranium and 1.277 Angstrom for the other], considered together with magnetization data and electronic and vibrational-spectra, support the following bonding model: U-IV=O=C-.-O- H <----> U-IV-O=C-O-. In these charge-separated resonance structures, the uranium center is oxidized to uranium(IV) and the CO2 ligand reduced by one electron.
  • H Nakai; XL Hu; LN Zakharov; AL Rheingold; K Meyer
    INORGANIC CHEMISTRY 43 3 855 - 857 2004年02月 [査読有り]
     
    Reaction of [(((Ad)ArO)(3)tacn)U(III)] (1) or [((Me(3)Si)(2)N)(3)U(III)] (3) with tetramethylimidazol-2-ylidene (Me(4)IMC:) yields novel N-heterocyclic carbene complexes [((Ad ArO)(3)tacn)U(III)(Me(4)IMC:)] (2) and [((Me(3)Si)(2)N)(3)U(III)(Me(4)IMC:)] (4). Uranium complexes 2 and 4 represent the first examples of compounds with an N-heterocyclic carbene ligand coordinated to a low-valent uranium center. The paramagnetic complexes 1, 2, and 4 were characterized by (1)H NMR, UV-vis-NIR, and EPR spectroscopy as well as SQUID magnetization measurements and X-ray diffraction analyses. DFT studies indicate a significant degree of pi-bonding in the U(III)-carbene entity.
  • Castro-Rodriguez, I; H Nakai; P Gantzel; LN Zakharov; AL Rheingold; K Meyer
    JOURNAL OF THE AMERICAN CHEMICAL SOCIETY 125 51 15734 - 15735 2003年12月 [査読有り]
  • H Nakai; YJ Tang; P Gantzel; K Meyer
    CHEMICAL COMMUNICATIONS 1 1 24 - 25 2003年 [査読有り]
     
    The synthesis and characterisation of a thallium(I) triscarbene complex of the chelating, tripodal carbene ligand 1,3,5-{tris(3-tert-butylimidazol-2-ylideno)methyl}-2,4,6-trimethylbenzene is reported, in which the thallium ion is coordinated by three N-heterocyclic carbene donors in a distorted trigonal planar environment.
  • H Nakai; S Ogo; Y Watanabe
    ORGANOMETALLICS 21 8 1674 - 1678 2002年04月 [査読有り]
     
    This paper reports on the first example of pH-dependent cross-coupling reactions of watersoluble organic halides (3-X(C6H4)CO2H, where X = Cl, Br, I) with organoboron compounds (PhB(OH)(2) and Ph4BNa) to form 3-Ph(C6H4)CO2H, catalyzed by the mononuclear organometallic aqua complex [(SCS)Pd-II(H2O)](2)(SO4) (1)(2)(SO4), SCS = C6H3-2,6-(CH2SBut)(2)) in basic media (8 < PH < 13, NaHCO3/NaOH buffers). The structure of 1(PF6) was unequivocally determined by X-ray analysis. The reactions show unique PH selectivity depending upon the organoboron compounds; i.e., the rate of the reactions with PhB(OH)2 shows a sharp maximum around PH 10, though the rate of the reactions with Ph4BNa shows a flat maximum in a PH range of about 8-11. The PH dependence is discussed on the basis of the pK(a), values of [1](2)(SO4) and PhB(OH)(2).
  • S Ogo; H Nakai; Y Watanabe
    JOURNAL OF THE AMERICAN CHEMICAL SOCIETY 124 4 597 - 601 2002年01月 [査読有り]
     
    This paper reports a pH-dependent H-2-activation {H-2 (pH 1-4) --> H+ + H- (pH -1) --> 2H(+) + 2e(-)} promoted by Cp*Ir complexes {Cp* = eta(5)-C-5(CH3)(5)}. In a pH range of about 1-4, an aqueous HNO3 solution of [Cp*Ir-III(H2O)(3)](2+) (1) reacts with 3 equiv of H-2 to yield a solution of [(Cp*Ir-III)(2)(mu-H)(3)](+) (2) as a result of heterolytic H-2-activation {2[1] + 3H(2) (pH 1-4) --> [2] + 3H(+) + 6H(2)O}. The hydrido ligands of 2 display protonic behavior and undergo H/D exchange with D+: [M-(H)(3)-M](+) + 3D(+) reversible arrow [M-(D)(3)-M](+) + 3H(+) (where M = Cp*Ir). Complex 2 is insoluble in a pH range of about -0.2 (1.6 M HNO3/H2O) to -0.8 (6.3 M HNO3/H2O). At pH -1 (10 M HNO3/H2O), a powder of 2 drastically reacts with HNO3 to give a solution of [Cp*Ir-III(NO3)(2)] (3) with evolution of H-2, NO, and NO2 gases. D-labeling experiments show that the evolved H-2 is derived from the hydrido ligands of 2. These results suggest that oxidation of the hydrido ligands of 2 {[2] + 4NO(3)(-) (pH -1) --> 2[3] + H-2 + H+ + 4e(-)} couples to reduction of NO3- (NO3- --> NO2- --> NO). To complete the reaction cycle, complex 3 is transformed into 1 by increasing the pH of the solution from -1 to 1. Therefore, we are able to repeat the reaction cycle using 1, H-2, and a pH gradient between 1 and -1. A conceivable mechanism for the H-2-activation cycle with reduction of NO3- is proposed.
  • H Fujihara; H Nakai
    LANGMUIR 17 21 6393 - 6395 2001年10月 [査読有り]
     
    This paper reports the preparation and characteristic property of a new nanocomposite gold cluster with fullerene as a carbon nanocluster, C-60-Au nanoparticles, together wit h the first account of electrochemical comparison of the C-60-Au nanoparticle films and the self-assembled monolayers of C-60-thiol 1 on gold electrodes. Octanethiol-stabilized gold nanoparticles were treated with a fullerene C-60-terminated alkanethiol. (1) to give new fullerenethiol-functionalized gold nanoparticles (C-60-Au nanoparticles) of 2 nm diameter with a very narrow size distribution. Immersion of a gold electrode in a solution of C-60-Au nanoparticles deposited the colloid films of them on the electrode surface which showed two distinct reversible reduction/oxidation waves and significant electrochemical stability. The C-60-Au nanoparticle films were firmly immobilized on the planar electrode by a simple self-assembly method without use of terminal ligand like bifunctional aminosiloxane or mercaptosiloxane. The electrochemical responses for the C60-Au nanoparticle films and self-assembled monolayers of C-60-thiol 1 adsorbed on gold electrodes are significantly different.
  • H Nakai; H Fujihara
    JOURNAL OF ORGANOMETALLIC CHEMISTRY 611 1-2 566 - 569 2000年10月 [査読有り]
     
    The preparation and properties of the self-assembled monolayers with oligo-ethyleneoxy linkages on flat and curved gold surfaces have been described. The electrochemical properties of the self-assembled monolayers of a tetrathiafulvalenyl-alkane monothiol and the ether-substituted alkane monothiol adsorbed onto gold electrodes showed no difference in their redox potentials and surface coverages. In contrast, the difference between the alkyl chain and the oxy-alkyl chain in the redox potentials and surface coverages was found in the self-assembled monolayers of the tetrathiafulvalenyl-tetrathiol and the ether-substituted tetrathiol adsorbed onto gold electrodes. The reaction of a thiol bearing oligo-ethyleneoxy linkages with octanethiolate-stabilized gold clusters gave the new oxy-Au clusters containing ether linkages which were dissolved in nonpolar and polar solvents. (C) 2000 Elsevier Science S.A. All rights reserved.
  • NAKAI Hidetaka; WATANABE Katsuhiko; ITO Seishiro; YOSHIHARA Masakuni; FUJIHARA Hisashi
    Journal of the Japan Society of Colour Material 73 7 325 - 329 一般社団法人 色材協会 2000年07月 [査読有り]
     
    Tetrathiafulvalenyl-thiol (1), disulfide (2), thioacetate (3), and sulfide (4) have been prepared. The redox behaviors of the tetrathiafulvalene derivatives (1-3) depended on the nature of an electrolyte and a solvent used. Though a difference of electrochemical behavior between 1 and 2 was found in the cyclic voltammograms, the self-assembled monolayers (SAMs) from 1 and 2 showed the similar redox behaviors, while, 4 did not form SAM on a gold (Au) electrode.
  • NAKAI Hidetaka; TSUCHIYA Youichi; WATANABE Katsuhiko; MATSUSHITA Tsuyoshi; ITO Seishiro; YOSHIHARA Masakuni; FUJIHARA Hisashi
    Journal of the Japan Society of Colour Material 73 4 176 - 181 一般社団法人 色材協会 2000年04月 [査読有り]
     
    The electrochemical property of alkane-tetrathiol or alkane-tetrapyrrole containing tetrathiafulvalene (TTF) and a new type of electropolymerization using the TTF-derivatized tetrathiol are described. Glassy carbon and gold electrodes have been modified by electropolymerization of the TTF-derived tetrathiol. The polymer films of the TTF-tetrathiol immobilized on glassy carbon and gold electrodes are remarkably stable to electrochemical recycling. The electrochemical behavior and the redox potentials of the polymer films of the TTF-tetrathiol depend on the nature of the counter anion of electrolyte or solvent. In contrast, the corresponding TTF-monothiol and TTF-tetrasulfide do not form the polymer films. The electrochemical property of the TTF-tetrathiol has been compared with that of the corresponding TTF-tetrapyrrole.
  • H Nakai; M Yoshihara; H Fujihara
    ELECTROCHEMISTRY 68 1 8 - 10 2000年01月 [査読有り]
     
    The electrochemical properties of the self-assembled monolayers of a tetrathiafulvalenyl-alkane monothiol (1) and the etcher-substituted alkane monothiol (1-0) adsorbed onto gold electrodes showed no difference in their redox potentials and surface coverages. In contrast, the difference between the alkyl chain and the oxy-alkyl chain in the redox potentials and surface coverages was found in the self-assembled monolayers and the electropolymerized films of the tetrathiafulvalenyl-tetrathiol (2) and the ether-substituted tetrathiol (2-0) adsorbed onto gold electrodes.
  • H Nakai; M Yoshihara; H Fujihara
    LANGMUIR 15 25 8574 - 8576 1999年12月 [査読有り]
     
    New electroactive gold nanoparticles containing tetrathiafulvalene (TTF-Au nanoparticles) of 2-4 nm diameter have been prepared by the reaction of octanethiol-derivatized gold nanoparticles with a tetrathiafulvalenyl monothiol. Immersion of a gold electrode in a solution of the colloidal TTF-Au nanoparticles deposited the colloid films of them on the electrode surface which were remarkably stable under repeated electrochemical cycling. Thus, the TTF-Au nanoparticle films were firmly immobilized on the electrode by a simple self-assembly method without use of a terminal ligand like bifunctional aminosiloxane or mercaptosiloxane. A three-dimensional network of TTF-Au nanoparticles cross-linked by tetrathiafulvalenyl tetrathiol was assembled on a gold electrode.
  • H Fujihara; H Nakai; M Yoshihara; T Maeshima
    CHEMICAL COMMUNICATIONS 8 737 - 738 1999年04月 [査読有り]
     
    Remarkably stable self-assembled monolayer and polymer films composed of a new tetrathiafulvalenyl-tetrathiol have been formed on metal electrodes: this is a new class of surface modification by self-assembly and electrochemical polymerization using the same alkane-tetrathiol.

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